The role of the Transgenic Shared Resource (TSR) is to assist investigators making use of transgenic models in their research and thereby to facilitate the use of this powerful technology to answer questions in cancer research. Specificially, the resource: 1) Provides assistance and advice regarding the design and execution of experiments employing transgenic and induced mutant mouse models, including scientific and regulatory issues; 2) Assists in the design, construction, and preparation of DNA constructs for the generation of novel transgenic mouse models; 3) Generates new transgenic mouse models for investigation by pronuclear injection and including all aspects of surgery, care, and husbandry of the animals; 4) Assist investigators with the genotyping of transgenic mice by performing tail biopsies, preparing genomic DNA and assaying for the transgene by PCR and/or Southern blot analysis; 5) Re-derives mouse models that are contaminated with pathogens by embryo transfer so that they can be used by LCC investigators; 6) Provides a sperm and embryo cryopreservation/In viro fertilization service to assist investigators in protecting their valuable mouse models from accidental loss, and to provide long-term banking of mouse models; 7) Provides knockout mouse production. The TSR was included as a component of the Animal Shared Resource at the last site visit. It has been utilized by 23 investigators from five programs. Since October 2001, seven new mouse models have been produced, and within the next few months, we expect a 60% increase in usage based on inclusion of transgenic mouse models proposed in recent R01 grant submissions. An overall accounting of projects utilizing the TSR shows that 94% were supported by peer-reviewed funding awarded to LCC members.